Yuan Class AIP & Kilo Submarine Thread


optionsss

Junior Member
The reason why I don't think it's a prototype is because of the sailess submarine they had earlier. The sailess sub is pretty much the same size, also single hulled, which is most likely a prototype/experimental platform. Why build two experimental sub of the same size, only 2 years apart. I see PLAN want something for the shallow waters within the first island chain. This can liberate the larger convential subs to patrol areas around the second island chain and indian ocean and gaining experience for the eventual long range patrol of the nuclear subs. China still have some Mings that want to replace. The yellow and east china sea only have a depth of 80 meters and not suitable for large submarine operation. The small sub is also useful to delivery frogman for special operations.
 

broadsword

Colonel
Prototypes don’t always scale up, sometimes it makes sense to scale down instead.

The main determining factor is cost and time, which in turn is largely driven by what’s available off the shelf.

If you were prototyping a new sub, it may make more sense to take off the shelf components and manufacturing facilities from existing SSKs than clean sheet everything from scratch.

If you want to repurpose as much existing tech and parts as possible, than that may well set a fairly large minimum practical size.

But I think we have gone as far as we can with what is currently available. We should get a better idea of what this is when better quality pictures emerge.

You don't think that would be still too big for an unmanned sub? You don't think it is still too early to make unmanned subs even for that size seen in the picture?

An unmanned sub's mission is probably narrowly defined. For that, a smaller size would do until the technology matures. On current technology, UUVs are lost and later hauled in by fishermen. If its mission were near equivalent to a manned sub, its size would probably look the picture, and either its undersea communication with the base has to be sound or its AI is well-proven.
 

Tam

Brigadier
Registered Member
Do we have any indications on the use of lithium ion batteries in Chinese SSKs? China has a world leading battery industry, so it seems outlandish to me that the PLAN wouldn't be interested in incorporating this technology.

There are some rumors that the '039C' might be using or testing lithium ion. Its funny that YouTuber Sub Brief mentioned this in his video.

I would think that Lithium Ion would need a safety validation before you put it on a manned sub. You heard that these batteries catch fire, and you don't want fires in a sub. If they want to test Lithium Ion you want it on an unmanned sub first.
 

Tam

Brigadier
Registered Member
The reason why I don't think it's a prototype is because of the sailess submarine they had earlier. The sailess sub is pretty much the same size, also single hulled, which is most likely a prototype/experimental platform. Why build two experimental sub of the same size, only 2 years apart. I see PLAN want something for the shallow waters within the first island chain. This can liberate the larger convential subs to patrol areas around the second island chain and indian ocean and gaining experience for the eventual long range patrol of the nuclear subs. China still have some Mings that want to replace. The yellow and east china sea only have a depth of 80 meters and not suitable for large submarine operation. The small sub is also useful to delivery frogman for special operations.

You can be testing two different technologies on two different subs. The newer one might be a manned one.

If I were to continue what I was talking about testing Lithium Ion for proof of concept submarines built for that purpose. I would like to test using LiFePo, which is a kind of Lithium Ion and one that is gaining rapid popularity among lower end EVs in China. LiFePo is the backbone of BYD's Blade battery for example, and Tesla is moving their lower end vehicles to it.

Conventional Lithium Ion uses Nickel Metal Hydride with cobalt, and that's the kind that got Chevy Bolts in trouble with fires, along with some Teslas too. NMH is the tech that the new Soryu derived class should be using as LiFePo is not used by any other manufacturer or country but in China. LiFePo has far greater heat tolerances, and doesn't produce as much heat, which makes it significantly safer. Another thing is that these batteries can survive a high degree of stress and puncture without exploding. The safety appeal of LiFePo makes it attractive for military applications. These batteries also have much longer recharge lifetime cycles, so they can remain in use a lot longer without being removed and recycled. Another advantage of LiFePo is that you can charge them at 100% and discharge them to a 100%, while NMH is at 80%/20%. They are also cheaper and doesn't use conflict minerals like Cobalt. They don't have the power density of NMH type Li Ion however, but their safety features allows them to be packed in much more denser formations which partly makes up for their lower power density, as NMH requires some space for ventilation. LiFePo also uses Phosphate, an element that is common in China, and LiFePo batteries are commonly built by battery makers in China.
 
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ZeEa5KPul

Major
Registered Member
There are some rumors that the '039C' might be using or testing lithium ion. Its funny that YouTuber Sub Brief mentioned this in his video.

I would think that Lithium Ion would need a safety validation before you put it on a manned sub. You heard that these batteries catch fire, and you don't want fires in a sub. If they want to test Lithium Ion you want it on an unmanned sub first.
Lithium iron phosphate batteries don't have that fire problem. I saw that video you mentioned, but I don't know how seriously to take him. It's certainly reasonable to assume the PLAN has at least explored this, I was wondering whether a "big shrimp" said anything about it.
 

Tam

Brigadier
Registered Member
Lithium iron phosphate batteries don't have that fire problem. I saw that video you mentioned, but I don't know how seriously to take him. It's certainly reasonable to assume the PLAN has at least explored this, I was wondering whether a "big shrimp" said anything about it.

I have some doubts about the 039C using Li Ion, even if it was rumored. I mean its still possible. I think Japan took a major risk using NMH style Li Ion with their Taigei class submarines, due to the obvious heat issues with this type of battery. Due to the safety issues with Lithium Ion, and even with something as safe as LiFePO, I would want a validation first with some prototype submarine, which can also be potentially unmanned, to reduce human risk as much as possible. This way you can convince yourself with proven data which can demonstrate to others. Once you are past the safety issue, Lithium Ion can be a game changer for conventional submarines.
 

optionsss

Junior Member
You can be testing two different technologies on two different subs. The newer one might be a manned one.

If I were to continue what I was talking about testing Lithium Ion for proof of concept submarines built for that purpose. I would like to test using LiFePo, which is a kind of Lithium Ion and one that is gaining rapid popularity among lower end EVs in China. LiFePo is the backbone of BYD's Blade battery for example, and Tesla is moving their lower end vehicles to it.

Conventional Lithium Ion uses Nickel Metal Hydride with cobalt, and that's the kind that got Chevy Bolts in trouble with fires, along with some Teslas too. NMH is the tech that the new Soryu derived class should be using as LiFePo is not used by any other manufacturer or country but in China. LiFePo has far greater heat tolerances, and doesn't produce as much heat, which makes it significantly safer. Another thing is that these batteries can survive a high degree of stress and puncture without exploding. The safety appeal of LiFePo makes it attractive for military applications. These batteries also have much longer recharge lifetime cycles, so they can remain in use a lot longer without being removed and recycled. Another advantage of LiFePo is that you can charge them at 100% and discharge them to a 100%, while NMH is at 80%/20%. They are also cheaper and doesn't use conflict minerals like Cobalt. They don't have the power density of NMH type Li Ion however, but their safety features allows them to be packed in much more denser formations which partly makes up for their lower power density, as NMH requires some space for ventilation. LiFePo also uses Phosphate, an element that is common in China, and LiFePo batteries are commonly built by battery makers in China.
I do believe this is a manned sub, but I don't see a lot of unique features that would require a purposely build test bed. Anything internal, such as new AIP system or sonar could be tested on the other facilities or the other purpose build test sub 032, which is much larger. Including this new sub, PLAN would have atleast 3 relatively large submaines just for testing purposes.
 

BoraTas

Senior Member
Registered Member
I have some doubts about the 039C using Li Ion, even if it was rumored. I mean its still possible. I think Japan took a major risk using NMH style Li Ion with their Taigei class submarines, due to the obvious heat issues with this type of battery. Due to the safety issues with Lithium Ion, and even with something as safe as LiFePO, I would want a validation first with some prototype submarine, which can also be potentially unmanned, to reduce human risk as much as possible. This way you can convince yourself with proven data which can demonstrate to others. Once you are past the safety issue, Lithium Ion can be a game changer for conventional submarines.
China has been using old 035s as testbeds too. Then there is a spotted midget sub and the sailless sub too. There may very well be secret test UUVs or midget subs we haven't seen. For some reason, I feel the new Yuan is a lot more formidable machine than most believe. We all saw how fast China progressed in everything. Wuhan shipyard also just announced it is a 60% new sub. The US intelligence has been publicly claiming China and Russia were cooperating in submarine designs too. I don't think Chinese conventional submarines are that behind German and Japanese ones.
 

para80

Junior Member
Registered Member
On the general note of "why so many test submarines" I will just note the Soviet test program was massive, they built all sorts of bespoke systems and adaptions for evaluation of various subsystems, concepts etc. Now I am not suggesting China by definition needs to go down that path but I suspect they do recognize both that undersea warfare is the inevitably dominant naval specialty going forward for various conflicts, and that they still have an awful lot of catch-up to do vis a vis other more established naval powers. I see a lot of determination, not to mention resources invested, to achieve just that.

Anyway, just a thought.
 

plawolf

Brigadier
You don't think that would be still too big for an unmanned sub? You don't think it is still too early to make unmanned subs even for that size seen in the picture?

An unmanned sub's mission is probably narrowly defined. For that, a smaller size would do until the technology matures. On current technology, UUVs are lost and later hauled in by fishermen. If its mission were near equivalent to a manned sub, its size would probably look the picture, and either its undersea communication with the base has to be sound or its AI is well-proven.

Current UUVs that are routinely lost and fished up are wave gliders designed to be disposable.

China has been making a lot of breakthroughs with underwater communications that might make large sized UUVs viable with current AI. Especially if operating in the shallower parts of the SCS.

But this design is such a close match to the MC209 model sahureka posted that it’s almost certainly that.
 

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